Field of the Invention
This invention relates to improvements in fluid delivery machines of the type of high pressure centrifugal pumps and turbo-compressors. It is known in the art that fluid centrifugal delivery machines, such as centrifugal pumps and turbo compressors which act by centrifugal force, of the type under discussion, consist of a frame in which there are formed a central part or housing containing an impeller blade rotor and a peripheral part in the form of a spiral chamber which surrounds the central part and constitutes the communication between the outlet end of the blade and the outlet of the machine. This arrangement normally corresponds to the requirements of pressures and duffuser heads which correspond to the different cross-sections of the head as they approach the outlet of the machine.
As is known, in accordance with the present state of the art, for a given centrifugal machine of the type under discussion, the operating curves of the diffuser chamber are continuous and have an optimal operating zone; the curve of the diffuser head as a function of the delivery output is substantially flat, which results in a considerable change in the output for small changes in the total head. This is not true for the curve of the efficiency as a function of the delivery, which shows a fully defined maximum which determines that if a better efficiency is desired, it is necessary to operate the machine with a given delivery and head, and thus there is no flexibility in the operating range of the machine with which the invention is concerned.
By the incorporating of the improvements provided in the invention it is possible to modify the geometry of the efficiency curves, making them discontinuous; in other words, making them with points of inflection or with zones of different curvature. Such an arrangement can make the operating conditions of a given machine flexible, which cannot be achieved with this type of machine in conventional structures.